Indian Prime Minister Narendra Modi in St. Petersburg, Russia.

Dmitry Lovetsky / Pool

India's Prime Minister Narendra Modi attends a signing ceremony after his talks with Russian President Vladimir Putin at the St. Petersburg International Economic Forum in St. Petersburg, Russia, Thursday, June 1, 2017. Modi's visit to Russia comes amid he and other world leaders expressed commitment to fighting climate change after U.S. President Donald Trump indicated that the U.S. might pull out of the Paris climate accords.(AP Photo/Dmitry Lovetsky, pool)

India's Prime Minister Narendra Modi attends a signing ceremony after his talks with Russian President Vladimir Putin at the St. Petersburg International Economic Forum in St. Petersburg, Russia, Thursday, June 1, 2017. Modi's visit to Russia comes amid he and other world leaders expressed commitment to fighting climate change after U.S. President Donald Trump indicated that the U.S. might pull out of the Paris climate accords.(AP Photo/Dmitry Lovetsky, pool) (Dmitry Lovetsky / Pool)

India's Prime Minister Narendra Modi attends a signing ceremony after his talks with Russian President Vladimir Putin at the St. Petersburg International Economic Forum in St. Petersburg, Russia, Thursday, June 1, 2017. Modi's visit to Russia comes amid he and other world leaders expressed commitment to fighting climate change after U.S. President Donald Trump indicated that the U.S. might pull out of the Paris climate accords.(AP Photo/Dmitry Lovetsky, pool)